Hello ziaro and Happy Christmas.
Some of these links might take you to where you can find further information.
There are aerobatic books available on Amazon.
Kershner's Basic Aerobatic Manual.
ASA: Skydancing.
Wolfgang Langewiesche: Stick and Rudder. (perhaps available in German or even Polish. He was a very interesting man and a Phd.
Aerobatics
IAC - International Aerobatic Club
Sean D. Tucker - Wikipedia, the free encyclopedia
AOPA Aerobatics Training with Ultimate High in the Cotswolds
Then of course you have these guys and they speak Polish too so perhaps you could drop them a line.
Zelazny Aerobatic Group - Polish display team
Orlik - Polish Air Force Aerobatic Display Team
Last but no means the least.
Pilot pomyli? lotniska <-- - Forum lotnictwa